There is a tendency during the laundering of fabrics for coloured fabrics to release dye into the wash solution. This is a most persistent and troublesome problem as this released dye can then be transferred onto other fabrics. A fabric treatment composition comprising an agent which could prevent the transfer of dye would therefore prove useful.
EP 462 806 (Unilever) discloses a domestic treatment of a fabric with a cationic dye fixing agent to reduce the amount of dye released from the fabric. Suitable cationic dye fixing agents include the dimethyldiallyl ammonium chloride polymer.
Surfactant containing dye transfer inhibiting compositions are disclosed in EP 0 587 550 (Procter and Gamble). The dye transfer inhibition agent is a polymer selected from polyamine N oxide containing polymers.
EP 0 327 927 (Procter and Gamble) describes a granular detergent additive comprising water-soluble polymeric compounds based on N-vinylpyrolidone and/or N-vinylimidazole and/or N-vinyloxazolidine and cationic compounds.
Detergent compositions comprising a N-vinylimidazole N-vinylpyrolidone copolymer are disclosed in EP 0 635 566 (Procter and Gamble). EP 0 635 566 teaches that surfactant systems excluding alkylbenzene sulphonate exhibit good dye transfer inhibition properties. However omission of LAS is detrimental to detergency.
The present invention has now found that dye transfer can be inhibited without loss of detergency by the use of selected levels of alkyl benzene sulphonate and a N-vinylimidazole N-vinylpyrrolidone copolymer. In addition to the prevention of dye transfer the formulations of the present invention exhibit excellent soil anti-redeposition properties and are high foaming. The formulations of the present invention are also particularly good at removing particulate and protein based soils from fabrics.